What is the evaluation and treatment approach for a patient presenting with hemiballismus?

Hemiballismus: Evaluation and Treatment

Immediate Diagnostic Evaluation

Hemiballismus requires urgent neuroimaging with MRI brain (with and without contrast) to identify the underlying etiology, most commonly stroke affecting basal ganglia structures, followed by assessment for metabolic causes—particularly nonketotic hyperglycemia—which has become increasingly recognized as a reversible cause. 1, 2

Critical History and Physical Examination Elements

• Document the precise characteristics of movements: involuntary, violent, coarse, wide-amplitude flinging movements involving ipsilateral arm and leg 1
• Assess for vascular risk factors: hypertension, diabetes, hyperlipidemia, and prior stroke history, as cerebrovascular disease is the most common etiology 1, 3
• Check blood glucose immediately: nonketotic hyperglycemia is an increasingly common and reversible cause, particularly in elderly patients with poorly controlled diabetes 2
• Evaluate for HIV status and immunosuppression: complications of HIV infection have emerged as a notable cause in recent years 1
• Determine symptom onset and progression: transient hemiballismus may represent reversible ischemic neurological deficit (RIND) or transient ischemic attack (TIA), indicating high risk for subsequent ischemic events 3

Neuroimaging Protocol

• MRI brain with and without gadolinium is the preferred imaging modality to identify lesions in the subthalamic nucleus, other basal ganglia structures (globus pallidus, caudate, putamen), or thalamus 1, 3
• MR angiography should be added to evaluate for severe carotid stenosis or occlusive disease, particularly when transient symptoms suggest TIA/RIND 3
• Note that CT may be insufficient: standard CT can miss small basal ganglia or thalamic lesions that are readily apparent on MRI 3

Essential Laboratory Workup

• Serum glucose and hemoglobin A1c: to identify nonketotic hyperglycemia as the cause 2
• Complete metabolic panel: to assess for other metabolic derangements
• HIV testing: should be considered given the increasing association with HIV-related complications 1

Treatment Approach

Address the Underlying Cause First

Treatment must be directed at the underlying etiology, as many patients experience spontaneous improvement or complete remission when the causative factor is corrected. 1, 2

• For nonketotic hyperglycemia: aggressive glucose control often leads to gradual resolution of symptoms over weeks to months, and symptomatic pharmacologic treatment may not be necessary 2
• For ischemic stroke/TIA: initiate antiplatelet therapy immediately and consider urgent vascular intervention for severe stenosis to prevent subsequent ischemic events 3
• For hemorrhagic stroke: manage blood pressure and provide supportive care 4

Symptomatic Pharmacologic Management

When symptomatic treatment is required, dopamine D2 receptor blockers are first-line therapy, with haloperidol being the most extensively studied agent. 1, 5

First-Line Agents

• Haloperidol: most commonly used neuroleptic, with demonstrated efficacy in reducing or eliminating hemiballistic movements 5

  • Historical case series showed that 11 patients treated with haloperidol had greatly reduced or eliminated movements, with none dying from the condition 5
  • Medication could be withdrawn within 6 months in 8 of 11 patients without recurrence 5

• Alternative atypical antipsychotics: olanzapine has shown significant efficacy when haloperidol fails 4

  • In one quantified case, olanzapine reduced hemiballistic movements by 87% in the upper extremity and 66% in the lower extremity during reaching tasks 4
  • May be better tolerated than typical antipsychotics with fewer extrapyramidal side effects 4

• Tetrabenazine: another effective option for symptomatic control, particularly as a dopamine-depleting agent 1

Surgical Treatment

• Pallidotomy is reserved for the minority of patients with severe, persistent, disabling hemiballismus that fails medical management 1
• Surgical intervention should only be considered after exhausting pharmacologic options and confirming that the condition is not self-limited 1

Prognosis and Monitoring

Contrary to older literature describing hemiballismus as having a grave prognosis, modern experience demonstrates that most patients have relatively good outcomes with appropriate treatment. 1, 5

• Spontaneous improvement is common: many patients experience gradual resolution, particularly when the underlying cause is treated 1, 2
• Medication can often be discontinued: in stroke-related cases treated with neuroleptics, drugs can frequently be withdrawn within 6 months without recurrence 5
• Monitor for recurrence: particularly in patients with transient symptoms suggesting TIA/RIND, as they remain at high risk for subsequent ischemic events 3

Critical Pitfalls to Avoid

• Do not dismiss transient hemiballismus as benign: it may represent TIA/RIND and indicate severe carotid stenosis requiring urgent intervention 3
• Do not overlook hyperglycemia: always check glucose levels, as nonketotic hyperglycemia is increasingly recognized and completely reversible with glucose control 2
• Do not assume subthalamic nucleus involvement: most patients in clinical-radiological series have lesions outside the subthalamic nucleus, involving other basal ganglia structures 1
• Do not confuse with seizure activity: obtain EEG if diagnostic uncertainty exists, as partial seizures can mimic involuntary movements 3
• Do not delay treatment in severe cases: while prognosis is generally good, severe persistent movements warrant prompt symptomatic treatment to prevent injury and improve quality of life 1, 5